Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene
Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene
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DOI：
10.1126/science.1110063
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发表时间：
2005-07
期刊：
影响因子：
56.9
通讯作者：
M. Pagani;J. Zachos;K. Freeman;B. Tipple;S. Bohaty
中科院分区：
文献类型：
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作者：
M. Pagani;J. Zachos;K. Freeman;B. Tipple;S. Bohaty
大气二氧化碳分压（pCO2）与古近纪气候之间的关系尚不清楚。我们使用从深海岩心中提取的二不饱和烯酮的稳定碳同位素值来重建从始新世中期到渐新世晚期（2.45亿到2500万年前）的pCO2。我们的研究结果表明，pCO2的范围在1000至1500百万分之一的体积在始新世中期至晚期，然后在渐新世下降的几个步骤，并达到现代水平的最新渐新世。二氧化碳分压的下降可能导致南极洲冰盖的临界扩张，并促进了迫使陆地C4光合作用开始的条件。
The relation between the partial pressure of atmospheric carbon dioxide (pCO2) and Paleogene climate is poorly resolved. We used stable carbon isotopic values of di-unsaturated alkenones extracted from deep sea cores to reconstruct pCO2 fromthe middle Eocene to the late Oligocene (∼45 to 25 million years ago). Our results demonstrate that pCO2 ranged between 1000 to 1500 parts per million by volume in the middle to late Eocene, then decreased in several steps during the Oligocene, and reached modern levels by the latest Oligocene. The fall in pCO2 likely allowed for a critical expansion of ice sheets on Antarctica and promoted conditions that forced the onset of terrestrial C4 photosynthesis.